Science of Synthesis

Sellars, J. D., Science of Synthesis Knowledge Updates, (2014) 1, 400.

Whilst p-block metals have found utility in the Friedel–Crafts reaction, so too have d-block metals. Group 4 metals such as sulfated or hydrated zirconium, titanium, and hafnium perfluorooctanesulfonate complexes have produced a range of excellent heterogeneous catalysts capable of producing aryl ketones from both acid chlorides and anhydrides at 5 mol% loading.[‌14‌–‌18‌] Moreover, hafnium(IV) bis(perfluorooctylsulfonyl)amide has been developed as a more robust, recyclable catalyst for Friedel–Crafts reactions. Comparing standard reactions of anisole and acetic anhydride in a fluorous (GALDEN SV) biphasic system reveals that the hafnium(IV) bis(perfluorooctylsulfonyl)amide catalyst continues to demonstrate excellent yields (>80%) of aryl ketone ‌1‌ after five reaction cycles, whereas the corresponding hafnium(IV) trifluoromethanesulfonate catalyst loses activity after the first reaction cycle (‌Scheme 5‌).[‌19‌,‌20‌]

‌Meeeee 8‌ Meeeeeeeee Meeeeee Meeeeeeee Meeeeee–Meeeee Meeeeeeee[‌88‌]

‌Meeeeeeeeee 8‌

Meeeeee(M) eeeeeeee, e eeeee 8 eeeee eeeeeeee, eee eeee eeeee eeeeeee ee e Meeeeee–Meeeee eeeeeeee ee eeeeeee, eee eeeeeee, 8-(8,8-eeeeeeeeeeeeeee)eeeeeeee (‌8‌) eeee 8,8-ee­eeeeeeeeeeeeee. Meee eee e-eeeee eeeee eeeeeeeee, eeeeeee(M) eeeeeeee eeeeeeee ee eeeeeeee eeee ee eeeeee(M) eeeeeeeeeee ee eeeeeeee eee eeeeeeee eeeeee eeeeeeeeeee eee eeeeeee eee eeeeeeeeeeee (‌Meeeee 8‌).[‌88‌]

‌Meeeee 8‌ Meeeeee(M) Meeeeeee Meeeeeeee Meeeeee–Meeeee Meeeeeeee[‌88‌]

Meeee e-eeeee eeeeee eeee eeee eeeeeeee eeeeeeeee eee eee Meeeeee–Meeeee eeeeeeee eeeeeee eeeeeeeeee(MM) eeeeeeeeee eeeeeee (MeM8Me8), eeeee ee 88 eee% eeeeeeeee eee eeeeeeee ee eeeeeeee-eeee eeeeee eeee eeee eeeeeeeee (‌Meeeee 8‌).[‌88‌]

‌Meeeee 8‌ Meeeeeeee Meeee ee Meeeeeeeeeeee Meeeeeee[‌88‌]

‌Meeeeeeeeee 8‌

Meee eeeeeeeeeee eeee eeee eeeeeeeeeeee eeeeeeeee eeeeeeeee eeeeeeee, eeee eeee(MMM) eeeeeee ee eeeeee eeeeeeeee eee eeeeeeee ee e eeeee ee eeeeee eee eeee eeeeeeeee eeeee eeeeeeeeee, eeeeeee eeee(MMM) eeeeeeee eeeeeeeee ee eeeee eeeeeee eeeeeee eee eeee eee ee eeeeeeee. Meeeeeee eeeeeeee-eeee eeeeee eeeee eeeeeeeeeeeeee, ee eeeeeeeeee eeee ee eee eeeeeeee ee ee eeeeeeee-eeeeeeeee eeeeeeeeee eeee eeeeeee eeeeeeee (‌Meeeee 8‌).[‌88‌–‌88‌]

‌Meeeee 8‌ Meeeeeeee Meeee Meee Meeeeeeee[‌88‌,‌88‌]

‌Meeeeeeeeee 8‌

Mee eeeeee eeeeeeeeee eeee eeee eeeeeeeee ee eeeeeeeeee e eeeeeee ee eeeeeeeeeee-8,8-ee­eeee, eeeee eeeeeee eeeee-eeeeeeee eeeeeeeeee eeeeeeee (‌Meeeee 8‌).[‌88‌]

‌Meeeee 8‌ Meeeeeeee ee Meeeeeee Meeeeeeeeee-8,8-eeeeee[‌88‌]

‌Meeeeeeeeee 8‌

Meeee eeeeee eeeeeee ee eeeeeeeeee eee Meeeeee–Meeeee eeeeeeeee eeeeeee eeeeeeeee eee eeee. Me eeeee-eeeeeeeee eeeeeeeee ee eeeeeeeeeeeee ee eeeeeeee eeee 88 eee% ee eeeeeeeeeeee(eeeeeeeeeeeeeeeeee)eeeeeeeee(MM) [MeMe8(MMe8)8] eee e eeeee eeeeee ee eeeeeeeee eeeeeeeee ee eeeeeee ee 888 °M.[‌88‌] Meee(MM) eeeee ee eeee(MM) eeeeeeeeeeeeeeeeeeeeeeeee eeeeeeeeeee [Me(MMe)8•8M8M] ee 88 eee% eeeeeeeeeee eeeeeee eee eeeeeeee ee eeeeeeee-eeee eeeeee eee eeeeeeeeeeeeeee eeee eeee eeeeeeeee.[‌88‌,‌88‌]

Meeeeeeeeeee Meeeeeeee

8-(8-Meeeeeeeeeeee)eeeeeeee (‌8‌); Meeeeee Meeeeeeee:[‌88‌]

Me e eeeeeee ee MMMMMM MM 888 (8.8 eM) eee eeeeeeeeeeeee (8.8 eM) eeee eeeee Me{M[MM8(MM8)8MM8]8}8 (88.8 ee, 8.88 eeee), eeeeeee (888.8 ee, 8.8 eeee), eee Me8M (888.8 ee, 8.8 eeee). Mee eeeeeee eee eeeeeee eeeeeeeeeeee ee 888 °M eee 8 e. Meee eee eeeeeeee eee eeeeeee, eee eeeeeee eeeeeee ee ee eee eeeeee eeeeee 8 eee eeee eee eeeeee eeeeee, e.e. ee eeeee eeeeeeeeeeeee eeeee eee e eeeee MM 888 eeeee. Meee ‌8‌ eee eeeeeeee eeee eee eeeee eeeee eeeee eeeeeeeeeeeeee (eeeeee eee); eeeee: 888.8 ee (88%). Mee eeeee eeeeeeee eeeee eeeeeeeeee eee eeeeeeee eee eeeeee ee eee eeeeeeeeee eeeeeeee eeeeee, ee eeeee eeeeeeeeeeeee (8.8 eM), eeeeeee (888.8 ee, 8.8 eeee), eee Me8M (888.8 ee, 8.8 eeee) eeee eeee ee eeee eeee. Mee eeeee eeeeeeeeee eee eeeeeeeee (e.e., eeeeeeee ee 888 °M eee 8 e, eeeeeee eeeeeeeeee) eeee eee eeee ee eeeeeeeee eeeee eee eee eeeee eeeee. Meee e eeeeeeeee eee eeeeeeee e eeeeeee eeee eeeee. Mee eeeeee ee ‌8‌ eeee 88, 88, 88, eee 88%, eeeeeeeeeeee, ee eeeee eeee eeee. Me eeeeeeee, eeeee 8.8 ee% eeeeeeee ee Me{M[MM8(MM8)8MM8]8}8 eeeeeeee eeee eee eeeeeeeeeeeee eeeee eee eeeeeeee (eeeeeeeeee ee eeeeee eeeeeeee eeeeeeeeeeee) ee eeee eeeee, eee 88% ee Me{M[MM8(MM8)8MM8]8}8 eeeeeeee ee eee eeeee eeeee eee eeeee eee.

8-(8,8-Meeeeeeeeeeeeee)eeeeeeee (‌8‌); Meeeeee Meeeeeeee:[‌88‌]

MMMMMMM: Meeeeeeeeeee ee eeeeeeeee, e eeeee- eee eeee-eeeeeeeee eeeeeeeee, eee ee eee, eeee, eee eeeeeeeeeee eeeee eeeeeeee.

Me e eeeeeee ee MeMe8 (8.8 ee, 8.88 eeee, 8 eee%) eee MeMeM8 (88.8 ee, 8.88 eeee, 8 eee%) eee eeeee MeMM8 (8.8 eM) eeeee eeeee, eee eee eeeeeee eee eeeeeee eee 88 eee ee ee. Meee, 8,8-eeeeeeeeeeeeeeee (888 ee, 8.88 eM, 8.8 eeee) eee Me8M (888.8 ee, 8.88 eM, 8.8 eeee) eeee eeeee ee ee. Meeee eee eeeeeee eee eeee eeeeeee eee 8.8 e ee 88 °M, eee eeeeeeee eee eeeeeeee eeee eee. MeMMM8 (8.8 eM). Mee eeeeeee eee eeeeeeeee eeee MM8Me8 (8 × 8 eM), eee eee eeeeeeee eeeeeee eeeeee eeee eeeeee eeee eeeee, eeeee (Me8MM8), eee eeeeeeeeeeee eeeee eeeeeee eeeeeeee. Meeeeeeeeeee ee eeeee eeeeee eeeeeeeeeeeeee (eeeeee eee, eeeeee/MeMMe 8:8) eeee eee eeeeeee ee e eeeeeeeee eee; eeeee: 888.8 ee (88%).

References